Pteris cretica
Environmental Weed (2024)
Common names
Cretan brake
Biostatus
Exotic
Conservation status
Not applicable
Category
Vascular
Structural class
Ferns
Detailed description
Large terrestrial fern. Rhizome short-creeping; scales minute, dark brown. Fronds dimorphic, clustered. Stipes 0.25–0.9 m long, yellow-brown, glabrous. Lamina 0.2–0.6 × 0.1–0.4 m, dark green (occasionally variegated) broadly oblong to oblong, 1-pinnate, often incompletely 2-pinnate (forked) at the base; primary pinnae in 2–7 widely spaced pairs, somewhat ascending, narrowly lanceolate, linear to linear-falcate, tapering to apices and long-acuminate with smooth or minutely denticulate margins, chartaceous, glabrous; rachis not winged or slightly winged at apex. Lower pinnae short-stalked, in mature plants with 1–3 posterior short-stalked free conform pinnules. Upper pinnae sessile, uppermost adnate to rachis. Terminal pinna slightly contracted; apex of sterile pinna, sharply dentate. Veins free, simply or once-forked; false veins absent. Sori continuous; indusium subentire; paraphyses numerous.
Similar taxa
Easily distinguished from all indigenous and naturalised Pteris except P. pacifica by the 1-pinnate fronds bearing long, narrow-lanceolate, linear to linear-falcate pinnae, with the basal few pairs often forked. From the very uncommon P. pacifica, P. cretica is readily distinguished by the typically dark green rather than yellow-green fronds, and by the distal portion of the sterile pinnae margins sharply dentate. Pteris cretica could be confused with P. vittata however that species has a much narrower frond, with a distinctly longer terminal pinna, and by the pinnae which are never forked and which reduce in size toward the frond base.
Distribution
Naturalised. New Zealand: North and South Islands (widespread from Whangarei south to Banks Peninsula). Indigenous to to the warm-temperate and tropical parts of the Old World.
Habitat
Coastal to montane (mostly coastal to lowland). A common weedy fern in many urban parts of New Zealand but also common in less modified areas growing in dense forest, along river, stream and gully banks, on track and roadside cuttings. It can be very common in wasteland areas within cities and towns, and often appears on retaining walls, and even under houses (provided there is some light).
Detailed taxonomy
Genus
Family
Endemic genus
No
Endemic family
No
Ecology
Year naturalised
1881
Origin
Tropics and temperate regions
Propagation technique
Pteris cretica is commonly cultivated and exists in a diverse range of forms which include the usually dark green plants, as well as variegated ones and those whose pinnae apices are much divided (i.e. “crested”). It is an aggressive fern that rapidly spreads and probably should not be cultivated anymore as it rapidly spreads from garden environments into indigenous habitats, especially coastal and lowland forest, along river, stream, and gully sides, and even wetlands. Pteris cretica is remarkably tolerant of a range of conditions but does best when planted in a semi-shaded to shaded site in a deep, humus enriched, moist soil.
Other information
Etymology
pteris: A fern known to the ancient Greeks; from the Greek pteris
Environmental Weed (2024)
This plant is named in a list of 386 environmental weeds in New Zealand 2024 prepared by DOC. 759 candidate species were considered for inclusion on this new comprehensive list of environmental weeds in New Zealand. The species considered were drawn from published lists of weed species, lists of plants that must be reported or managed by law if observed, existing national and regional programmes and agreements for pest management, and species already managed by the Department of Conservation (DOC). Candidate species were then assessed to see if they were fully naturalised and whether they have more than minor impacts in natural ecosystems. Read the full report here.
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
PTECRE
Referencing and citations
References and further reading
Brownsey PJ, Smith-Dodsworth JC. 2000. New Zealand Ferns and Allied Plants. David Bateman, Auckland, NZ. 168 p.
Kramer KU, McCarthy PM. 1998. Pteridaceae. Flora of Australia 48, Ferns Gymnosperms and allied groups: 241–248. ABRS/CSIRO Victoria, Australia.
Attribution
Fact Sheet Prepared for NZPCN by: P.J. de Lange (18 January 2012). Description adapted from Brownsey & Smith-Dodsworth (2000) and Kramer & McCarthy (1998).